REVCO  Huh? What wrong with APE? Me APEd for many years with no problem. Don't point finger at APE. APE good not bad.  
(Version 3.8.2)

XENOPHILE  Avoid.

Unsanity APE is an unsupported hack that accesses Mac OS X processes that Apple has delcared off limits. All too often, I've identified APE as a cause of system instability or application weirdness when troubleshooting Macs. Any potential user of APE needs to ask themselves if they really need the functionality it enables, and if so, can they afford extra system down time as the price for this functionality?   
(Version 3.8.2)

MACINSPORE  This software is downright dangerous and insane. Based on my testing you have a very high likelihood of getting an "out of range" error and the loss of your display. Recovery from this problem is NOT simple.

1st Reboot you Mac and hold down the command, option, p and r keys. If your lucky this will fix things (it did not for me)

2nd find another monitor, plug it in and reboot. This fixed things things on a G3 running Jaguar.

3rd hold down the option and S keys while rebooting your Mac and delete the "com.apple.windowserver.XXXXX.plist" exist file in your own /Users/yourname/Library/Preferences/ByHost folder. Time to test your knowledge of UNIX and the "rm" command

But if this does not do the trick for you perhaps you could buy a new Mac or pay the Author, he claims he will try to help :-)

I tried this software on 3 Macs and got the same error: two Intel Macs (Tiger and Leopard) and a G3 tower (Jaguar) (1 Compaq Monitor, 1 HP Monitor 1 Apple Studio Display)

And yes I love too test software for the Mac, been doing so for over ten years. This software made me work hard to recover the display in each case.

the Author seems to be a good fellow and has been around the Mac OS for years (probably longer than I have and thats a long time) - but frankly this software is not ready for prime time on the Mac OS X  
(Version 3.8)

SMTIPS  Oh MAN!! I was just about to get this because for some stupid reason I can only get a 60Hz refresh rate through the Displays panel when my monitor supports 75Hz. I think it's stupid that a mac with a 256 Nvidia card will only show a single refresh rate available when the monitor will support higher. It's ALWAYS been a problem with Macs way back since System 7 that the res/refresh rates that COULD be supported weren't selectable in the system...DUHHHH on you apple!!

Anyway....Unsanity APE has been known to cause FAR FAR too many issues. I refuse to use it, and you just lost my money...I was all ready to buy this til I saw the below comment...forget that APE CRAP.  
(Version 3.7.11)

JAMESKITTY  Requires Unsanity's APE hack. I won't install it.

Too bad the author can't find a way of programming this within Apple's rules.  
(Version 3.7.10)

APPLECRYPT  i wish the interface was better, but you had my reg money a while back and now it even works on intel mac!! Xcellent!  
(Version 3.7.2)

ORION  I *hate* the tendency of games to always select stretched 4:3 resolutions on my Cinema Display, thus making everything look wider than it should be, and making me slighly nauseous. I looked everywhere for a program that would remove stretched modes from the list of resolutions.

SwitchRes doesn't do that. It does have a feature that "disables" certain resolutions but it doesn't actually remove them from the list. When a program tries to switch to a disabled resolution, SwitchRes makes the switch silently fail, keeping the previous resolution. This is a bad thing -- for games this often means a bunch of garbage on the screen.

But what SwitchRes does allow me to do is "redirect" a video mode to a different one. So, for instance, if a program tries to switch to 640 x 480 (stretched), I can have it actually switch to 640 x 480 (not stretched). This works like a charm. Now I can finally play all my games with the proper aspect ratio!

Oh, and it also has a displays menu that isn't crippled like Apple's, but that's really just a bonus. For the ability to remove stretched video modes from my life, SwitchRes was well worth the $15.  
(Version 3.6)

JIMW  This product may have a use in special circumstances but it would seem to me that for the majority of users simply checking "Show Displays in Menu Bar" in the "Displays Preferences" should suffice.   
(Version 3.5.1)

STRIDER  just registered with kagi :)

thank you!  
(Version 3.4)

DJ  wots with u lot? Mac noobs perhaps???

I've been using switchres for months without troubles, 100% rock solid s/w! Well worth the reg! Only hope it works with Tiger as it's pre-ordered here =D  
(Version 3.4)